Ornate Adamantium Breastplate has 150 more armor and 1 more defense at the cost of 16 strength and 4 stamina. I don't think the strength gain and minor stamina gain is worth the cost in defensive stats; armor is king.

I would add DMC: Mal to the aoe trinket list. Procs from Ww and cleaves which you spam in AoE > HoJ.

Also Force of will > Mark of chosen for AoR tanking, proc is up a lot and 25 damage reduction per hit on an AoE pack is strong. Still use it for Suppression room over onxyia trinket when i am grabbing all the whelps.

EDIT #4 (2019-04-21): Made changes on some gear recommendations, added some and removed others due to research, more theory crafting and an over-all changes in the 1.12.1 warrior META over the last couple of years.The list in its current state has been adapted to fit 1.12.1 gearing choices. If Classic wow ends up using progressive itemization, disregard some of the items listed.

The protection META of vanilla has gone through a big shift, away from the old way of thinking about defense and the mis-guided gospel of the def-cap. This is no longer considered the main priority. Focus Lies in balancing EHP/Health pool (basically a mix of defensive stats and health) along side with a higher focus on threat capabilities